Proteome and miRNome profiling of microvesicles derived from medulloblastoma cell lines with stem-like properties reveals biomarkers of poor prognosis.

Primary central nervous system (CNS) tumors are the most common deadly childhood cancer. Several patients with medulloblastoma experience local or metastatic recurrences after standard treatment, a condition associated with very poor prognosis. Current neuroimaging techniques do not accurately detect residual stem-like medulloblastoma cells promoting tumor relapses. In attempt to identify candidate tumor markers that could be circulating in blood or cerebrospinal (CSF) fluid of patients, we evaluated the proteome and miRNome content of extracellular microvesicles (MVs) released by highly-aggressive stem-like medulloblastoma cells overexpressing the pluripotent factor OCT4A. These cells display enhanced tumor initiating capability and resistance to chemotherapeutic agents. A common set of 464 proteins and 10 microRNAs were exclusively detected in MVs of OCT4A-overexpressing cells from four distinct medulloblastoma cell lines, DAOY, CHLA-01-MED, D283-MED, and USP13-MED. The interactome mapping of these exclusive proteins and miRNAs revealed ERK, PI3K/AKT/mTOR, EGF/EGFR, and stem cell self-renewal as the main oncogenic signaling pathways altered in these aggressive medulloblastoma cells. Of these MV cargos, four proteins (UBE2M, HNRNPCL2, HNRNPCL3, HNRNPCL4) and five miRNAs (miR-4449, miR-500b, miR-3648, miR-1291, miR-3607) have not been previously reported in MVs from normal tissues and in CSF. These proteins and miRNAs carried within MVs might serve as biomarkers of aggressive stem-like medulloblastoma cells to improve clinical benefit by helping refining diagnosis, patient stratification, and early detection of relapsed disease.

Endothelial progenitor cells and vascular endothelial growth factor in patients with Takayasu's arteritis.

BACKGROUND: Endothelial progenitor cells (EPCs) are responsible for endothelial damage repair. Takayasu's arteritis (TA) is a chronic inflammatory disease that affects large vessels. The aim of the study was to evaluate the number of EPCs and the levels of vascular endothelial growth factor (VEGF) and the relationship of these variables in patients with TA. METHODS: Thirty women with TA and 30 healthy controls were included. EPCs were assessed by flow cytometry and cell culture and VEGF quantification was performed by commercial ELISA kits. RESULTS: Ages of patients and controls were similar. The number of EPCs in patients and controls (median (interquartile range) were 0.0073% (0.0081%) vs. 0.0062% (0.0089%), p = 0.779 by flow cytometry and 27.0 (42.3) colony forming units (CFUs) vs. 27.0 (20.5) CFUs, p = 0.473 by cells culture, respectively. VEGF levels in patients and controls was 274.5 (395.5) pg/ml vs. 243.5 (255.3) pg/ml, p = 0.460. There was no difference in the number of EPCs and VEGF level between patients with active and inactive disease. There was a tendency of the number of angioblast-like EPCs in patients taking anti-TNFs to be higher; and in patients using methotrexate to be lower. CONCLUSION: No significant difference was found in the quantification of EPCs and VEGF levels in TA patients compared to controls, and no difference was observed between patients with active and inactive disease.

Adipose Tissue-Derived Stem Cells Reduce Acute and Chronic Kidney Damage in Mice.

Acute and chronic kidney injuries (AKI and CKI) constitute syndromes responsible for a large part of renal failures, and are today still associated with high mortality rates. Given the lack of more effective therapies, there has been intense focus on the use stem cells for organ protective and regenerative effects. Mesenchymal stem cells (MSCs) have shown great potential in the treatment of various diseases of immune character, although there is still debate on its mechanism of action. Thus, for a greater understanding of the role of MSCs, we evaluated the effect of adipose tissue-derived stem cells (AdSCs) in an experimental model of nephrotoxicity induced by folic acid (FA) in FVB mice. AdSC-treated animals displayed kidney functional improvement 24h after therapy, represented by reduced serum urea after FA. These data correlated with cell cycle regulation and immune response modulation via reduced chemokine expression and reduced neutrophil infiltrate. Long-term analyses, 4 weeks after FA, indicated that AdSC treatment reduced kidney fibrosis and chronic inflammation. These were demonstrated by reduced interstitial collagen deposition and tissue chemokine and cytokine expression. Thus, we concluded that AdSC treatment played a protective role in the framework of nephrotoxic injury via modulation of inflammation and cell cycle regulation, resulting in reduced kidney damage and functional improvement, inhibiting organ fibrosis and providing long-term immune regulation.

miR-367 promotes proliferation and stem-like traits in medulloblastoma cells.

In medulloblastoma, abnormal expression of pluripotency factors such as LIN28 and OCT4 has been correlated with poor patient survival. The miR-302/367 cluster has also been shown to control self-renewal and pluripotency in human embryonic stem cells and induced pluripotent stem cells, but there is limited, mostly correlational, information about these pluripotency-related miRNA in cancer. We evaluated whether aberrant expression of such miRNA could affect tumor cell behavior and stem-like traits, thereby contributing to the aggressiveness of medulloblastoma cells. Basal expression of primary and mature forms of miR-367 were detected in four human medulloblastoma cell lines and expression of the latter was found to be upregulated upon enforced expression of OCT4A. Transient overexpression of miR-367 significantly enhanced tumor features typically correlated with poor prognosis; namely, cell proliferation, 3-D tumor spheroid cell invasion and the ability to generate neurosphere-like structures enriched in CD133 expressing cells. A concurrent downregulation of the miR-367 cancer-related targets RYR3, ITGAV and RAB23, was also detected in miR-367-overexpressing cells. Overall, these findings support the pro-oncogenic activity of miR-367 in medulloblastoma and reveal a possible mechanism contributing to tumor aggressiveness, which could be further explored to improve patient stratification and treatment of this important type of pediatric brain cancer.

The use of mesenchymal stem cells in bladder augmentation.

PURPOSE: To compare integration of bladder acellular matrix (BAM) with the bladder when seeded with mesenchymal stem cells (MSC) and when MSC are injected intravenously (IV). METHODS: MSCs were isolated from bone marrow of EPM-1 Wistar male rats. Female rats were distributed into: Group A-BAM augmentation; Group B-BAM augmentation and MSCs IV administered; Group C-BAM-MSC seeded augmentation. Animals were killed on postoperative days 7, 14 and 28. Morphological analyses were performed using hematoxylin and eosin and Masson's trichrome, in addition to immunohistochemical staining with α-SMA and neurofilament for assessment of tissue repair. RNAm expression of the SRY gene was used to mark MSCs in the rats killed on postoperative day 28. RESULTS: The muscle layer was best repaired in Groups B and C. No difference in the repair of the urothelium in the animals in any of the three groups was found. Group B presented the smallest inflammatory reaction and the best neural repair on postoperative day 28. None of the animals examined had MSCs in their bladder graft. CONCLUSION: The MSCs were able to improve repair of the muscle layer and when injected intravenously, they were noted to initiate the neuronal regeneration process.